Eductor jet pump and method

ABSTRACT

An eductor jet pump including a venturi throat mounted at the input end of a discharge line into which a high velocity fluid jet nozzle is directed. Hydraulic cylinders and a hydraulic control circuit provide for relative movement of the jet nozzle toward or away from the venturi throat for either pulsating operation by regular cycling of the nozzle portion, for specific control of efficiency by nozzle position, or for closing the venturi throat to prevent backflow.

O United States Patent 11 1 1111 3,816,027 Miscovich [451 Jun 11, 1974[54] EDUCTOR JET PUMP AND METHOD 1,133,601 3 1915 Wood 417/183 1,671,5645/1928 Andrews.. 417/184 X [75] Inventor: mm Orange Cahf- 2,608,15711/1952 Conery 417/82 73 Assignee; Marcona Corporation, San 2,933,1054/1960 Jer1nan.... 91/216 B Francisco Calif 3,043,107 7/1962 Ma aus417/184 x 3,093,088 6/1963 Ventress.. 417/54 [22] Filed: Sept. 20, 1973,472,026 10/1969 Conabee.. 91/462 X [2]] App] NO 398 981 3,598,5048/1971 Siravo 417/184 R l t d Us, A li ti D t Primary Examiner-CarltonR. Croyle [63] Continuation of $61. No. 181,017, Sept. 16, 1971,ExammerRlchard Gluck abandoned.

[57] ABSTRACT [52] US. Cl 417/184, 417/191, 302/15 n or jet pumpincluding a venturi throat [51] Int. Cl F04f 5/48, 865g 53/30 m unted ah input end of a discharge line into [58] Field of Search 91/462, 218,216 B; i h a high velocity flui jet nozzle is directed. Hy- 417/183,184, 76, 82, 170, 191, 188; 302/57, draulic cylinders and a hydrauliccontrol circuit pro- 15 vide for relative movement of the jet nozzletoward or away from the venturi throat for either pulsating oper- [56]References Cited ation by regular cycling of the nozzle portion, forspe- UNITED STATES PATENTS cific control of efficiency by nozzleposition, or for H7 808 8 87 l Pangbam 91/218 closing the venturi throatto prevent backflow. 466:213 12/1891 6 Claims, 4 Drawing Figures Beard417/183 I ELASTOMERIC 1 LINING EDUCTOR JET PUMP AND METHOD This is acontinuation, of application Ser. No. 181,017 filed Sept. 16, 1971, nowabandoned.

This invention relates to eductor jet pumps and to methods of theiroperation in which a high velocity fluid is passed through a venturithroat to create a lifting force for material in the vicinity of thethroat opening. In one particular application, the eductor jet pumpfinds use in the dewatering of settled slurries over a wide range ofelevations such as is encountered in the progressive loading anddewatering of supernatant liquids from settled mineral ore slurriesaboard ships. The following particular description will be set forth inconnection with such slurry dewatering. However, it should be understoodthat the eductor jet pump of the present invention will find many otheruses, including that of a variable metering device, or a solids orslurry pump and the like.

In the loading of pulpable slurries of mineral ores aboard ships or intoother vessels, it is required that the suspending liquid beprogressively eliminated before or in the course of transporting suchmaterial from the point of loading to destination. As the liquid isremoved from the freshly loaded material, its volume may be restored byadditional slurry and liquid, a compact economically transportable massis obtained which is not free flowing so that vessel stability isobtained.

The present invention finds particular use in the ship loading of ore ormineral solids in slurrified form in which the iron ore is of a magnetictype which has been crushed, milled and beneficated to produce discreteparticulate solids, the bulk of which may have a size ranging down from100 mesh. The dry specific gravity of the ore may be of the order of 4.5and the settling rate in water as a suspending liquid is relativelyhigh. Typically, such ore solids are pulped with water to form pumpableslurries which contain at least 60 percent and up to 80 percent solids.The present eductor jet pump permits the elimination or removal ofsupernatant water from such settled slurries after they have been loadedinto holds.

Heretofore, eductor jet pumps have been used for removing suchsupernatant liquids but they have not been entirely satisfactory due tothe high pumping heads that are often required when pumping from deepwithin the holds and the change in head which results from the change inlevel of supernatant water during successive cycles of loading. That isto say, initially dewatering takes place from deeper portions within thehold of the ship, while at later stages of loading, the pump operates atmore elevated positions. Present pumps do not account for the change inefficiency due to this change in the pumping head. Furthermore, whenpumping against a high head from deep within a vessel, the pump issubject to back flooding of the entire head standing in the dischargeline when the same is turned off. Such flooding can result insubstantial inefficiencies since a considerable volume of water isrelaesed back into the freshly dewatered slurry. There is, therefore, aneed for a new and improved eductor jet pump for use in the removal ofsupernatant liquids from settled slurries.

In general, it is an object of the present invention to provide aneductor jet pump and method which will overcome the limitations anddisadvantages by the foregoing use of a variable relationship betweenthroat and a high velocity fluit jet.

Another object is to provide an eductor jet pump and method of the abovecharacter which facilitates the eliminating of settled supernatantliquid from previously suspended slurries.

Another object of the invention is to provide an eductor jet pump andmethod of the above character which will facilitate cyclic loading anddewatering of ore slurries to insure solidified non-shifting cargoduring transit.

Another object of the invention is to provide an eductor jet of theabove character in which the venturi throat cross section is variableduring operation and which can be shut off completely to prevent backflow.

Another object of the invention is to provide an eductor jet pump andmethod of the above character in which the efficiency is variable andmay be adjusted to suit the operation at various elevations.

Another object of the invention is to provide an eductor jet pump andmethod of the above character in which venturi throat cross section isvaried regularly over a given cycle interval to provide pulsatingoperation.

The eductor jet pump and method of the present invention areparticularly suitable for the dewatering of settled slurries in shipsholds and includes a discharge line terminating at its outer end in ajet nozzle which is directed into the throat. The nozzle is mounted forreciprocal movement towards and away from the throat to allow meteringof the intake flow or to permit closure with the nozzle to shut thesection flow off entirely. A hydraulic circuit is provided through theaction of suitable cylinders to control the position of the jet withrespect to the throat. Such position may be adjusted to a fixed positionto control metering of flow through the throat or may be set for cyclicoperation in which the jet is moved toward and away from the throatthrough a given number of strokes per minute to thereby providepulsating operation. These and other objects and features of theinvention will become apparent from the following description and claimswhen taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view partiallybroken away of an eductor jet pump constructed in accordance with thepresent invention, the hydraulic control circuit of which is shownschematically.

FIG. 2 is a cross-sectional view taken along the lines 22 of FIG. 1.

FIG. 3 is a cross-sectional view taken along the lines 33 of FIG. 1.

FIG. 4 is a top plan view partially broken away of another embodiment ofan eductor jet pump constructed in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The followingdescription will be given in connection with the installation of aneductor jet pump and its use aboard ship, particularly for thedewatering of supernatant liquid from settled slurries. Typically,mineral slurries of this type settle rapidly and into a lower zonewherein the solids are in direct physical contact overlaid with the zonein which the solids are still in the process of settling and the thirdor upper zone which is essentially quiescent and clarified liquid fromwhich the solids are removed. Eventually a wall defined plane ofdemarcation develops between the settling and settled zones and theupper zone of essentially clear liquid. The present inventioncontemplates removing of the suspending liquid by lowering the eductorjet pump of the present invention into the clarified supernatant liquidand pumping the same off, after which additional slurry may be pumped inand progressively dewatered in the same manner.

Accordingly, referring to FIGS. 1 through 3 there is shown an eductorjet pump of the present invention which includes a discharge linemounted on the suitable support structure such as bulkhead (not shown).The discharge line is of relatively large diameter and is connected by aswivel union (not shown) to a discharge conduit leading overboard. Theother end of the discharge line may be supported by a hoisting davitprovided on the upper deck having a block and line connected to a padeye at the outer end of the discharge line. The lower end of thedischarge line terminates in means forming a venturi throat 12 whichpreferably is bell-shaped in a continuous annular curve.

A high velocity input line 14 is provided for supplying fluid, such as aliquid, and includes a jet nozzle 16 at its lower end directed coaxiallyinto the venturi throat in an operating position proximate thereto.Suitable means are provided for supporting the input line insubstantially parallel relation to the discharge line and for moving thelower portion thereof so that the nozzle 16 can be brought towards andaway from the venturi throat 12. Such means takes the form of a seriesof yokes 18, 20 rigidly attached to the discharge line and carryingbushed guides 22, 24 thereon for receiving the moveable portion 25 ofthe input line. An additional yoke 26 is attached to the input line at aposition such that an extension thereof in the form of a guide shoe 27rides on the discharge pipe immediately above the venturi nozzle to aidin preventing gross rotation of the members about each other. The lowerend of the input line is U-shaped so that the nozzle 16 is directed incoaxial relationship toward the venturi throat. As shown in FIGS. 1 and3, a plurality of straightening vanes 29 are mounted to extend radiallyfrom the input line walls to aid in reducing vortex formation andresulting turbulence and thereby increase the efficiency of the jet.

A resilient lining 28 is provided on the interior walls of the venturithroat. Preferably such lining is elastomeric and may be constructed ofa suitable rubber-like formulation such as one of the urethane rubbers.The exterior of the nozzle is so sized that with respect to the throat,that when the nozzle is brought up into the throat, sealing contact ismade with the elastomeric lining to thereby close the throat as a checkvalve to seal the same against backwash in the reverse direction downthe discharg line.

Actuator means are provided at the upper end of the input line forvarying and controlling the position of the nozzle either at someselected location or for reciprocating the same during the operation ofthe eductor. Such means takes the form of a bell 30 mounted at the upperend of the input line section 25 and forming a cylinder. The portion 25of the input line between the bell and nozzle is thus moveable beingsupported for reciprocating motion in guides 22, 24. A fixed portion 32of input line 14 is supported on discharge line 10 by a suitable doubleyoke support 34 and extends downwardly into the cylinder formed by thebell. The bell is provided with a pair of spaced seals 36, 38 whichengage the side wall of the downwardly extending fixed portion of inputline. The input line carries a fixed position piston 40 which togetherwith the bell defines a volume of a double acting cylinder together withthe seals 36, 38. The ends of the cylinder are provided with hydraulicinlets 42, 44 so that the cylinder and the associated lower end of thedischarge of the input line may be given up or down by application ofhydraulic pressure difference on an appropriate side of the piston 40.

able portion 25 of the input line and the associated noz zle andconsists of a parallel circuit including in one branch a four-wayhydraulic valve 45 having opera tional outputs 46, 48 connected to theinlets 42, 44 on each side of the cylinder and a drain or relief line 49passed through a metering valve 50 which partially controls the speed ofmovement of the apparatus. Screw adjustable limit stops 52, 54 arecarried on the cylinder and actuate a level control 61a on an auto valve51 forming the other branch of the circuit, and indicate the desiredextremes of limited travel of the cylinder up or down, as indicated bythe dotted outline 59 showing the uppermost or closed position. Thestops serve to operate the auto valve and thereby reverse the pressuredistribution and the direction of travel of the moveable input line ateach extreme. Fluid pressure to the auto valve is supplied through atakeoff line and a main shut-off valve 60 from the high pressure inputline Means are provided for sensing the nature of the material flowingin the discharge line and for overriding the hydraulic control circuitsto thereby close the venturi throat on the occurrence of certainpredetermined conditions. Such means consists of suitable sensors 61, 62mounted on the discharge line. Sensor 61 is responsive to flow in thedischarge line and operates upon cessation of the flow to energize thesolenoid 68 on valve 45 to close the throat and prevent backwash. Sensor62 senses solids content, as in the case of magnetic iron ore bymeasuring changes in the magnetic field. When the ore solids contentbecomes too great, sensor 62 energizes the second solenoid 64 on valve45 to close the nozzle in the throat. When the discharge line is closedcompletely, high pressure water is the only element introduced into thedischarge line and acts to force any obstruction of high solids loadout.

Together, the actuator means and the control circuit serve to permitcontinuous control of the nozzle throat opening during the operation ofthe eductor.

Thus, the present invention provides considerable flexibility inoperation by permitting most efficient use at variable levels by movingthe relative position of the nozzle to the throat to control the amountof throat opening. When pumping maximum depths the throat nozzle openingis narrowed to restrict the amount of material taken in and therebydevelop a higher pumping head. In cyclic loading operations in whichslurries are successively loaded and dewatered, the eductor is higher atthe end of the loading cycle and the pumping head reduced. At that timethe throat can be opened up to take up the maximum volume. When thenozzle is in completely closed position, it compresses against therubber lining 28 of the throat and makes a completely tight seal. Byusing such a lining it is also possible to reduce the possibility of arock holding the nozzle in partially opened position. Of course, at theend of each loading cycle, the throat is closed and the eductor moved upout of the way from the receiving vessel so that additional slurry canbe pumped in. Thus, the adjustable feature of the present eductor allowsuse of maximum efficiency of the venturi throat opening whichcorresponds to various elevations and the volume of liquid decreases asthe nozzle closes the throat area. And, the eductor lift does not stallas it would if the nozzle were used in a fixed single position.Additionally, by shutting off the eductor, backflooding of the standinghead in the discharge line back is completely prevented.

In addition to the using of the adjustable throat feature, the presentinvention can also be operated in a reciprocating mode in which thenozzle is moved toward and away from the throat over a predetermineddistance and during a predetermined cycle time to vary the rate inamount of eduction for supply to the liquid charge being educted. Inthat mode of operation, the adjustable limit stops 52, 56 on themoveable portion 14 of the intake line serve to drive the operatinglever 51a on the auto valve 51. By adjusting metering valve 50, the rateof movement of the intake line may be adjusted to determine the numberof cyles per minute which are used. Generally, repeat time in the rangeof about 1 to 5 seconds for each complete cycle is found satisfactory.When so arranged, the jet automatically reciprocates and in each cyclegulps in a load of liquid which then moves up the throat and is pushedout of the discharge line. Meanwhile the eductor retracts to pick upanother load and proceeds continually to discharge the liquid in aseries of pulsations. Such operation is expected to be most useful inpumping slurries with the present eductor.

Referring now to FIG. 4, there is shown an alternative embodiment of theinvention utilizing a pair of double acting cylinders 80, 82 mounted oneach side of the fixed portion 84 of the input high pressure line andhaving actuating arms 86, 88 extending downwardly to connect to asuitable flange 90 carried on the moveable portion 92 of the input linewhich is sealed to the fixed portion for sliding movement by suitablesingle packing 94. This arrangement facilitates construction of thepresent invention utilizing conventionally available components.

An additional feature illustrated in FIG. 4 concerns the lateralposition control of the nozzle. At the lower end of the bell 12 formingthe venturi. throat there is provided an outwardly extending annular rim96 having guide holes therein. The end of the input line immediatelybeneath the nozzle is provided with an annular flange 98 carrying guiderods 99, 100 mounted in alignment with the guide holes in the rim 96 andin alignment with the desired movement of the nozzle toward the venturi.In this way, forces subjected to the eductor during its operation willbe unable to carry the nozzle too far out of misalignment and therebyeither hinder its ability to seat into closure if desired or impair itsefficiency by lateral mispositioning. The foregoing embodimentsillustrate operation in which the throatnozzle relationship isdetermined by movement of the nozzle and portions of the associatedfluid supply. It is obvious that the discharge line could,alternatively, be constructed to move relative to a fixed nozzle byinterchanging certain parts between the respective lines. Accordingly,any procedure for rapidly adjusting the relative positions of the throatand nozzle should be comprehended within the scope of the presentinvention.

While there has been disclosed herein certain specific embodiments inorder to illustrate the carrying out of the present invention, it shouldbe understood that they are to be taken in the illustrative sense, asmany changes and adaptations of the present invention will occur tothose skilled in the art to which it pertains. For example, while therehas been shown the use of a hydraulic system for controlling the inletline 14 position driven from the high pressure line supply itself, aseparate hydraulic circuit could be used and even operate on a differentmedia such as oil. In fact, it even is possible to use mechanicalactuators with some loss in ease of operation. Many other applicationsof the invention besides dewatering of slurries will suggest themselvesto those skilled in the art. For example, the eductor jet pump of thepresent invention should find direct application as a proportioningdevice in which an additive is to be mixed with a slurry or liquid as infire fighting applications. Also, the use of air, air-liquid mixtures,or other gas and gas-liquid mixtures could be used in the high pressurejet supply where the additional buoyancy created was required to obtainsatisfactory lift. Accordingly, the invention should be construedbroadly, and should only be limited by the scope of the appended claims.

I claim:

1. Eductor jet pump apparatus for removing liquids or liquid suspendedmaterial from a pool thereof, comprising a discharge line having oneopen end thereof adapted to be lowered into said pool, bell meansforming a venturi throat at said one end of the discharge line anddefining an inlet opening at the lower end thereof for receivingmaterial directly from said pool, a highvelocity liquid input linehaving upper and lower portions, said upper portion having one endthereof adapted to be connected to a source of liquid under pressure,means forming an upwardly directed jet nozzle at the end of the lowerportion of said input line, guide means for carrying said input line inparallel alignment alongside said discharge line said guide meansserving to align the nozzle in operating position proximate the end ofsaid discharge line and directed into said venturi throat, said guidemeans being constructed and arranged to permit said lower portion andsaid jet nozzle to move in opposite directions towards and away fromsaid throat and in axial alignment therewith to thereby vary theeffective area of said inlet opening exposed to said pool, meansinterconnecting said upper and lower portions for movement relative toeach other and forming a seal therebetween, hydraulic actuator meansmechanically connected between said upper and lower portions of saidhigh-velocity input line for positively moving said lower portion andsaid jet nozzle relative to said throat during operation of the jet pumpto thereby regulate the efficiency of said eductor, and means forcontrolling said hydraulic actuator means so that the relative positionof said nozzle and throat is selectively maintained in accordance withthe setting of the control means.

2. An eductor jet pump as in claim 1, in which said venturi throat isprovided with an elastomeric lining to provide a closure seat for saidjet nozzle, and in which the outer configuration of said jet-nozzle isadapted to engage said elastomeric lining to form a seal.

3. An eductor jet pump as in claim 1, in which said hydraulic actuatormeans for moving said jet nozzle includes a double-acting hydrauliccylinder, and a fourway auto valve having operational outputs connectedto each side of said cylinder, said auto valve including sensing meansfor determining the limits of travel of said hydraulic cylinder means tothereby reverse its direction of motion at each limit of travel.

4. An eductor jet pump, as in claim 1, in which said actuator meansinclude means for repeatedly cycling said nozzle between a partiallyopened and more fully opened positions.

5. An eductor jet pump apparatus for removing liquids or other materialfrom a pool thereof, a discharge line having an open end thereof adaptedto be lowered into said pool, bell means forming a venturi throat atsaid end of said discharge line defining an inlet opening at the lowerend thereof, a high-velocity fluid input line, including an upwardlydirected jet nozzle formed at a remote end thereof, means mounting saidhighvelocity fluid input line relative to said discharge line such thatsaid jet nozzle is aligned in an operating position proximate anddirected into said venturi throat, means for moving said jet nozzlerelative to said throat for varying the position of said jet nozzle withrespect to said throat and thereby the effective area of said inletopening exposed to said pool for regulating the efficiency of saideductor, at least one guide rod, means for supporting said guide rod onone of said venturi throat bell and jet nozzle, and means carried on theother of said throat and jet venturi nozzle for slidably guiding saidguide rod to prevent lateral motion thereof as the venturi throat andjet nozzle are relatively moved toward and away from each other.

6. Eductor jet pump apparatus for removing liquids or other materialsfrom a pool thereof, comprising a discharge line having an open endthereof adapted to be lowered into said pool, bell means forming aventuri throat at said lower open end of said discharge line anddefining an inlet opening exposed to said pool, a liquid input linehaving an upper portion adapted to be connected to a source of liquidunder pressure and a lower portion mounted for movement relative to saiddischarge line, an upwardly directed jet nozzle formed at the lower endof said lower portion, means carrying said liquid input line such thatthe said jet nozzle is aligned in an operating position proximate anddirected to said venturi throat, means for moving said jet nozzle andthroat relative to each other during operation of the same for varyingthe position of said jet nozzle with respect to said throat and therebyvarying the effective area of said inlet opening for regulating theefficiency of said eductor jet pump, said means for moving said jetnozzle including a double-acting hydraulic actuator concentricallydisposed about a movable portion of said high-velocity liquid inputline, said actuator being connected between the movable portion and afixed portion of said liquid input line said actuator including a pistoncarried on one of said portions of said input line.

1. Eductor jet pump apparatus for removing liquids or liquid suspendedmaterial from a pool thereof, comprising a discharge line having oneopen end thereof adapted to be lowered into said pool, bell meansforming a venturi throat at said one end of the discharge line anddefining an inlet opening at the lower end thereof for receivingmaterial directly from said pool, a highvelocity liquid input linehaving upper and lower portions, said upper portion having one endthereof adapted to be connected to a source of liquid under pressure,means forming an upwardly directed jet nozzle at the end of the lowerportion of said input line, guide means for carrying said input line inparallel alignment alongside said discharge line said guide meansserving to align the nozzle in operating position proximate the end ofsaid discharge line and directed into said venturi throat, said guidemeans being constructed and arranged to permit said lower portion andsaid jet nozzle to move in opposite directions towards and away fromsaid throat and in axial alignment therewith to thereby vary theeffective area of said inlet opening exposed to said pool, meansinterconnecting said upper and lower portions for movement relative toeach other and forming a seal therebetween, hydraulic actuator meansmechanically connected between said upper and lower portions of saidhigh-velocity input line for positively moving said lower portion andsaid jet nozzle relative to said throat during operation of the jet pumpto thereby regulate the efficiency of said eductor, and means forcontrolling said hydraulic actuator means so that the relative positionof said nozzle and throat is selectively maintained in accordance withthe setting of the control means.
 2. An eductor jet pump as in claim 1,in which said venturi throat is provided with an elastomeric lining toprovide a closure seat for said jet nozzle, and in which the outerconfiguration of said jet nozzle is adapted to engage said elastomericlining to form a seal.
 3. An eductor jet pump as in claim 1, in whichsaid hydraulic actuator means for moving said jet nozzle includes adouble-acting hydraulic cylinder, and a four-way auto valve havingoperational outputs connected to each side of said cylinder, said autovalve including sensing means for determining the limits of travel ofsaid hydraulic cylinder means to thereby reverse its direction of motionat each limit of travel.
 4. An eductor jet pump, as in claim 1, in whichsaid actuator means include means for repeatedly cycling said nozzlebetween a partially opened and more fully opened positions.
 5. Aneductor jet pump apparatus for removing liquids or other material from apool thereof, a discharge line having an open end thereof adapted to belowered into said pool, bell means forming a venturi throat at said endof said discharge line defining an inlet opening at the lower endthereof, a high-velocity fluid input line, including an upwardlydirected jet nozzle formed at a remote end thereof, means mounting saidhigh-velocity fluid input line relative to said discharge line such thatsaid jet nozzle is aligned in an operating position proximate anddirected into said venturi throat, means for moving said jet nozzlerelative to said throat for varying the position of said jet nozzle withrespect to said throat and thereby the effective area of said inletopening exposed to said pool for regulating the efficiency of saideductor, at least one guide rod, means for supporting said guide rod onone of said venturi throat bell and jet nozzle, and means carried on theother of said throat and jet venturi nozzle for slidably guiding saidguide rod to prevent lateral motion thereof as the venturi throat andjet nozzle are relatively moved toward and away from each other. 6.Eductor jet pump apparatus for removing liquids or other materials froma pool thereof, comprising a discharge line havIng an open end thereofadapted to be lowered into said pool, bell means forming a venturithroat at said lower open end of said discharge line and defining aninlet opening exposed to said pool, a liquid input line having an upperportion adapted to be connected to a source of liquid under pressure anda lower portion mounted for movement relative to said discharge line, anupwardly directed jet nozzle formed at the lower end of said lowerportion, means carrying said liquid input line such that the said jetnozzle is aligned in an operating position proximate and directed tosaid venturi throat, means for moving said jet nozzle and throatrelative to each other during operation of the same for varying theposition of said jet nozzle with respect to said throat and therebyvarying the effective area of said inlet opening for regulating theefficiency of said eductor jet pump, said means for moving said jetnozzle including a double-acting hydraulic actuator concentricallydisposed about a movable portion of said high-velocity liquid inputline, said actuator being connected between the movable portion and afixed portion of said liquid input line said actuator including a pistoncarried on one of said portions of said input line.